st: re: unable to compute for collinearity diagnostics

Hi Statalisters,
I am having a bit of a problem in computing for the collinearity diagnostics after running my logistic regression model. I tried running the command 'collin', and stata returned the following results:
(obs=1103)
matrix has missing values
r(504);
( [P] error . . . . . . . . . . . . . . . . . . . . . . . . Return code 504
matrix has missing values;
You have issued a matrix command attempting a matrix operation
that, were it carried out, would result in a matrix with missing
values; dividing by zero is a good example. )
I tried running the 'collin' command for my other logistic regression models and it worked just fine. There's just this one model where it doesn't seem to work. I checked all my observations and none of them have missing values. Would appreciate any help on how to remedy this problem
Also, is it valid to just use the Variance Inflation Factor computed if i ran the model in OLS instead of logistic?
Thanks!
Regards,
Kouji Asakura
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